Gliederung

Objective: Among spinal cord vascular malformations the presumably acquired dural AV fistulae must be distinguished from the intradural malformations which are likely to be inborn. While the occurrence of these entities per se is already rare, the concurrence of two of these vascular malformations in the same patient is an extraordinary finding. We report on a 35-year-old patient who harboured both a dural AV fistula and an intradural perimedullary fistula.

Methods: This 35-year-old patient was admitted to our hospital because of a half-year history of hypaesthesia of both legs and a strain-exacerbating spastic paraparesis which was slowly progressive. On MRI the spinal cord was slightly swollen and demonstrated an intramedullary hyperintensity from Th6 to Th12 on T2 weighted images. Spinal angiography revealed a shunt of TH 6 on the right side without an intervening nidus, that was fed by a radiculomeningeal artery and that drained into ascending perimedullary veins. After injection into the Th5 intercostal artery, a small posterolateral artery was identified that, again without an intervening nidus drained into descending and ascending perimedullary veins. Upon surgery, both the perimedullary and the dural AV fistulae were identified, confirmed and subsequently obliterated.

Conclusions: While the frequency of double spinal dural AV fistulae is presumed to be around 2%, the combination of a dural and an intradural fistulae is exceedingly rare, with only two other reported cases in the literature. One might speculate, whether the alteration in venous drainage caused by the (presumably inborn) perimedullary fistula could possibly promote the production of a second, dural fistula due to elevated pressure with concomitant venous stagnation and subsequent thrombosis. We conclude, that despite the rarity of dual pathology, the clinician should be aware of the possibility of the concurrence of more than one spinal shunt in the same patient.